I bought this magic box from a retiring machinist who said that it is some sort of early VFD that he had built by an automation control company in Allentown PA in the 1980's or 1990's to run a 7.5HP 16x60 lathe on single phase power. I talked to the gentleman for over an hour and he seemed to be a straight shooter but didn't remember many details about the unit. We used it to power up an unloaded 3HP 3 phase motor at his shop and verified that the speed control did adjust the motor rpms. He wanted less than the cost of a bottle of whisky for it, so I took a chance.
The components seem kind of similar to the early 1980's VFD pictured here but I cant identify enough similarities to be sure what it is?
What is a Variable Frequency Drive?
The unit appears to be really well made and the heat sink that makes up the entire bottom of the unit looks sized for a high amperage application, but the other components don't seem like they are sized for a 7.5HP load. Does anybody have any thoughts on what this could be or how to determine its capacity?
The components seem kind of similar to the early 1980's VFD pictured here but I cant identify enough similarities to be sure what it is?
What is a Variable Frequency Drive?
The unit appears to be really well made and the heat sink that makes up the entire bottom of the unit looks sized for a high amperage application, but the other components don't seem like they are sized for a 7.5HP load. Does anybody have any thoughts on what this could be or how to determine its capacity?